Climate change impact on China food security in 2050

Climate change is now affecting global agriculture and food production worldwide. Nonetheless the direct link between climate change and food security at the national scale is poorly understood. Here we simulated the effect of climate change on food security in China using the CERES crop models and the IPCC SRES A2 and B2 scenarios including CO2 fertilization effect. Models took into account population size, urbanization rate, cropland area, cropping intensity and technology development. Our results predict that food crop yield will increase +3-11 % under A2 scenario and +4 % under B2 scenario during 2030-2050, despite disparities among individual crops. As a consequence China will be able to achieve a production of 572 and 615 MT in 2030, then 635 and 646 MT in 2050 under A2 and B2 scenarios, respectively. In 2030 the food security index (FSI) will drop from +24 % in 2009 to -4.5 % and +10.2 % under A2 and B2 scenarios, respectively. In 2050, however, the FSI is predicted to increase to +7.1 % and +20.0 % under A2 and B2 scenarios, respectively, but this increase will be achieved only with the projected decrease of Chinese population. We conclude that 1) the proposed food security index is a simple yet powerful tool for food security analysis; (2) yield growth rate is a much better indicator of food security than yield per se; and (3) climate change only has a moderate positive effect on food security as compared to other factors such as cropland area, population growth, socio-economic pathway and technology development. Relevant policy options and research topics are suggested accordingly

A protocol of Chinese expert consensuses for the management of health risk in the general public

IntroductionNon-communicable diseases (NCDs) represent the leading cause of mortality and disability worldwide. Robust evidence has demonstrated that modifiable lifestyle factors such as unhealthy diet, smoking, alcohol consumption and physical inactivity are the primary causes of NCDs. Although a series of guidelines for the management of NCDs have been published in China, these guidelines mainly focus on clinical practice targeting clinicians rather than the general population, and the evidence for NCD prevention based on modifiable lifestyle factors has been disorganized. Therefore, comprehensive and evidence-based guidance for the risk management of major NCDs for the general Chinese population is urgently needed. To achieve this overarching aim, we plan to develop a series of expert consensuses covering 15 major NCDs on health risk management for the general Chinese population. The objectives of these consensuses are (1) to identify and recommend suitable risk assessment methods for the Chinese population; and (2) to make recommendations for the prevention of major NCDs by integrating the current best evidence and experts’ opinions.Methods and analysisFor each expert consensus, we will establish a consensus working group comprising 40–50 members. Consensus questions will be formulated by integrating literature reviews, expert opinions, and an online survey. Systematic reviews will be considered as the primary evidence sources. We will conduct new systematic reviews if there are no eligible systematic reviews, the methodological quality is low, or the existing systematic reviews have been published for more than 3 years. We will evaluate the quality of evidence and make recommendations according to the GRADE approach. The consensuses will be reported according to the Reporting Items for Practice Guidelines in Healthcare (RIGHT)

NTIRE 2024 Challenge on Low Light Image Enhancement: Methods and Results

This paper reviews the NTIRE 2024 low light image enhancement challenge, highlighting the proposed solutions and results. The aim of this challenge is to discover an effective network design or solution capable of generating brighter, clearer, and visually appealing results when dealing with a variety of conditions, including ultra-high resolution (4K and beyond), non-uniform illumination, backlighting, extreme darkness, and night scenes. A notable total of 428 participants registered for the challenge, with 22 teams ultimately making valid submissions. This paper meticulously evaluates the state-of-the-art advancements in enhancing low-light images, reflecting the significant progress and creativity in this field.Comment: NTIRE 2024 Challenge Repor

Remote Sensing-Based Extraction and Analysis of Temporal and Spatial Variations of Winter Wheat Planting Areas in the Henan Province of China

The aim of this study is to assess the winter wheat planting (WWP) area in Henan Province and investigate its temporal and spatial variations by using remote sensing (RS) technology. A spectral angle mapper (SAM) was adopted to identify the WWP area of each district divided by the hierarchical grades of land surface drought index during 2001-2015. The results obtained show the expediency of monitoring the WWP areas at the regional scale via drought regionalization, which provides a goodness-of-fit R2 =0.933, a mean relative error MRE=49,118 ha, and an overall accuracy up to 90.24%. The major WWP areas in Henan Province were located in Zhoukou, Zhumadian, Shangqiu, Nanyang, and Xinxiang prefecture-level cities. Two representative sites are mountainous districts, with rich water resources or high urbanization rate, which have a low probability of WWP. Both sites exhibited a strongly manifested evolution of WWP areas, which could be attributed to extremely cold weather conditions, crop alternation, the popularization of new varieties, and fast expansion of built-up areas. The results of this study are instrumental in the analysis of crop planting variation characteristics, which should be taken into account in the further decision-making process related to the crop planting strategies

A Spectral-Mixing Model for Estimating Sub-Pixel Coverage of Sea-Surface Floating Macroalgae

In the past decade, floating macroalgae blooms have been increasing on a global scale. Sub-pixel coverage of floating macroalgae in a remote-sensing image is a crucial parameter for the estimation of biomass. In this study, in situ spectra of green macroalgae (Ulva prolifera), brown macroalgae (Sargassum horneri), and sea water were collected, and they were used to simulate the spectra of macroalgae-seawater mixtures in a linear mixing way. Three algae indices, normalized difference of vegetation index (NDVI), difference of vegetation index (DVI), and virtual-baseline reflectance height for floating algae (VB-FAH) derived from the spectra, were examined with the coverage of macroalgae. The results show that all three indices increase monotonically with increasing sub-pixel coverage of macroalgae: VB-FAH and DVI increase linearly, while NDVI shows a logarithmic increase. Based on this characteristic, two sub-pixel coverage models were proposed (i.e., a linear model based on VB-FAH (or DVI) and an exponential model based on NDVI). These models were then applied to the multiple-spectral GaoFen-1 (GF-1, 16m resolution) satellite image to examine the sub-pixel coverage of green tide in the Yellow Sea caused by the bloom of floating green macroalgae (U. prolifera). The results show that the relative differences between the two models are no more than 5%, indicating good consistency between the two models. Taking into account the sensitivity of these models (or indices) to the coverage of macroalgae, as well as atmospheric and sea surface conditions and their simplicity, we suggest using the linear model based on VB-FAH, DVI, or a similar band-difference index to estimate sub-pixel coverage of floating macroalgae

Study on corrosion resistance of HAZ and TMAZ in friction stir welding joint of 7075 aluminum alloy by thermal simulation

It is difficult to characterize the variation of corrosion resistance of the narrow areas in friction stir welding (FSW) joints due to the large temperature gradient. In this paper, the welding thermal simulation was performed to simulate the heat affected zone (HAZ) and thermo-mechanical affected zone (TMAZ) of the FSW 7075-T6 aluminum alloy, and the corrosion resistance and microstructure of the simulated samples were studied. Results show that the corrosion potential changes greatly under different thermal simulation temperatures. The pitting corrosion of the HAZ simulated samples presents two pitting potentials, but for the TMAZ simulated samples, two pitting potentials will gradually evolve to one pitting potential with the increase of the maximum temperature. The electrochemical impedance spectroscopy results show that the corrosion mechanism of the HAZ and TMAZ is completely inconsistent, which is related to the differences in precipitate and grain characteristics